Hydraulic jack



Feb. 19, 1924;- k 1,484,265

' J. B. HIRD ET AL HYDRAULIC JACK Filed July 20. 1922 y I iijhi INVENTORS 5/8/11? 5.11111! |./b/JIY 3' H4212 J2.

wag/1M ATTORNEY e-- to Patented Feb. 19, 1924.

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UNITED S'TA 1,484,265 PATENT OFFICE.

JOHN B. HIRD AND JOHN B. HIRD, JR., 0]? SEATTIIE, WASHINGTON, ASSIGNOBS, BY

DIRECT AND MESNE ASSIGNMENTS, 'IO IDEAL MACHINERY COMPANY, A CORPORA- TION OF WASHINGTON.

Application filed July 20,

T 0 all whom it may concern:

'Be it knownthat we, JOHN B. Hum and JOHN B. Hum, Jr., citizens of the United States, residing at Seattle, in the county of King and State of lVashington, have invented a certain new -and,useful Improvement in Hydraulic Jacks, of which the following is a specification.

Our invention relates to improvements in hydraulic jacks, and the object of our improvement is to provide a hydraulic jack that is strong and simple in construction, reliable and efficient in operation, easy to handle, easy and convenient to operate, not liable to get out of order, not expensive to manufacture and capable of lifting and sus-, taining a comparatively heavy load with a minimum amount of effort.-

Another object of the invention is to provide a hydraulic of this nature embodying a frame mounted on wheels, and having one orvmore hydraulic jack devices secured on the forward end thereof and arranged to be operated by an oscillating lever located near the rear end of the frame, said hydraulic jack devices also having release mechanism connected therewith and arranged to be operated from the rear end of the frame independently of said oscillating lever.

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawings.

In the drawings Figure 1'is a plan view of a hydraulic jack constructed in accordance with our invention.

Figure 2 is a view in vertical mid section of the same certain parts being shown in elevation.

Fi ure 3 is a fragmentary sectional view on' a arger scale showing parts of the pump and relief valve mechanism of the device.

Figure 4 is a plan view of a modified form of the invention in which two hydraulic jack devices are used'instead of one. Like reference numerals designate like parts throughout the several views.

Referring to the drawings, we have shown.

a frame comprising two side pieces 5 and 6 that are rigidly connected at their front -ends, by U bolts 7, with a transverse axle.

8 that has wheels 9 mounted thereon to support the front end of the frame. The rear ends of the frame pieces 5'and 6 are HYDRAULIC JACK.

1922. Serial No. 576,199.

arranged closer together than the front ends and are secured to a cross piece .10 which is supported on a caster wheel 11.

Disposed between the forward ends of the frame pieces 5 and 6 is a housing. designated generally by the numeral 12, that is 18 located above the pump. cylinder and communicating with the pump cylinder by a passageway 20. i

The forward end of the liquid reservoir communicates by a passageway 21 with the upper portion of the pressure cylinder 15 and further communicates through a relief valve 22 with the passageway 17 that communicates with the bottom end of the pressure cylinder 15. An opening arranged to be closed by a screw plug 23 is provided 'in the top of the liquid reservoir 18 through which the same may be filled with oil or other suitable liquid.

A hollow plunger 24 is reciprocably-disposed within the pressure cylinder 15, said plunger being of smaller diameter than the cylinder 15 throughout the greater portion of its length to leave a narrow passageway 25 between the plunger wall and the cylinder wall and being of larger diameter at the lower end to fit snugly within the cylinder and having a cup shaped packing member 26 secured to the bottom end thereof by a. disk 27 and screw 28. The plunger 24 is supported at the top of the cylinder 15 by a metal packing ring or bushing 30.

The plunger 24 is of hollow or tubular construction for the reception of a lifting shank 31 that is adjustable vertically of the plunger by means of a pin 32 that may be inserted in different transverse holes 33 in said lifting shank. The lifting shank terminates in a head 34 of any suitable form to engage with an object to be lifted.

- A piston 36 1S reciprocably disposed within the pump cylinder 16, said piston being provided with an internally disposed check valve 37 and being connected with a piston rod 38 that projects rearwardly through a gland 40 in the rear end of the cylinder 16.

The piston rod 38 is connected by a link 41 with a downwardly protruding lug 42 on a pump lever 43. The pump lever 43 is mounted for oscillation on ashaft 44 that extends crosswise through suitable bearing members 45 on the frame pieces 5 and 6.

The relief valve 22 may be of the ball check type as shown and may be arranged to be opened against the pressure of liquid by a pin 46 on the end of a rod 47 that projects rearwardly through a gland 48 in the end of the reservoir 18 and is connected with-the end of a relatively short lever 50 that is secured to a bent rod 51 which is fulcrumed in one of the bearing members 45 and forms a foot pedal by which the rod 47 may be moved to open the relief valve 22. A compression spring 49 on the rod 47 normally tends to move the rod outwardly.

In Figure 4 we have shown a triangularly generally by the numeral 54.

The jacks 54 of Figure 4 are each provided with a re'arwardly projecting piston rod 55 that is guided in suitable bracket-s 56 and is connected by a link 57 with a common lever 58 that is mounted-for oscillation on the frame 52. 1

The jacks 54 are each further provided with relief valves of a form hereinbefore we I plained that are arranged to be opened by rods 60 that are connected with independent foot levers 61 and 62 respectively, located near the rear end of the frame 52 so that either jack 54 may be released without releasing the other jack.

connection with motor vehicles where it is often necessary to lift one wheel of the vehicle or one end of the vehicle off of the support on which it rests. The jack may be convenientlymoved about by grasping the lever 43 and wheeling the jack in much the same manner that aohand truck would be wheeled. When it is to be used/for lifting motor vehicles the front end of the frame may bepushed under the vehicle until the head 34 of the lifting shank 31 is directly below the axle or other part of the vehicle upon which the lift is to be exerted. The

foot lever 51 is then raised to permit the relief valve 22 to close and the pumplever 43 is oscillated, thereby reciprocating the piston 36, forcin liquid into the bottom of the pressure ey inder 15 and lifting the not liable to get out of order. This jack is intended primarily for use in-- thereby moving the rod 47 forwardly and opening the relief valve 22 so that liquid may flow out of the cylinder, 15 into the reservoir 18. As the piston 15 is raised in=lifting a load the passageway 21 will be uncovered before the enlarged part on thebottom end of the piston strikes against the packing ring 30 thus allowing liquid to flow from the pressure cylinder directly into the reservoir 18 and preventing injury to the jack mechanism.

In case any liquid leaks past the piston 26 it will enter the annular space 25 between the wall of the cylinder 15 and the wall of the plunger 24 and return to the reservoir 18 through the passageway 21, thereby precluding the possibility of any leakage at the upper end of the cylinder 15.

The device shown in Figure 4 when used for lifting a motor vehicle may be inserted under either end of the same so that one of the jack members will engage with the axle or other part of the vehicle near each wheel thereby making it possible to lift the entire end of a vehicle and forming a substantial support for the vehicle after it is lifted. By having independent release means connected with each of the jacks 54 it is possible to lift one jack without lifting the other'or to release one jack'and lower one side of a vehicle without lowering the other side. a

This jack is strong, and substantial in construction, easy to operate, easy to move around, capable of lifting and sustaining a heavy load, lifts with asteadyeasy motion, will not-drop a load but will lower. the same slowlyand gradually when released, is capable of withstanding rough usage and is The foregoing description! and accompanying drawings clearly disclose what we now consider to be a preferred form of the invention, but it will be understood that this disclosure is merely illustrative aind that suchchanges in the same may be made as are within'the 500 e of the following claims...

What we claim, 1s: 1 1. A lifting jack embodying a relatively long wheel supported frame, verticall operable. hydraulic lifting jack -mec anism 2. A liftin jack embodying a wheel sup-'- ported frame, hydraulic jack mechanism for operating said hydraulic jack mechanism and foot operated release means connected with said hydraulic jack mechanism and operable from the rear end of said frame.

3. A lifting jack embodying a wheel supported frame, a vertically arranged hydraulic cylinder on the front end of said frame,'a lifting plunger in said hydraulic-cylinder, a pump cylinder" communicating with said hydraulic cylinder, a reciprocable piston in said pump cylinder, a check valve interposed between said pump cylinder and said hydraulic cylinder, a liquid reservoir connected with said pump cylinder and said hydraulic cylinder, a release valve interposed between said liquid reservoir and said hydraulic cylinder, a longitudinally reciprocable rod for opening said release valve and a foot pedal on the rear end of said frame for moving said rod.

4:. A lifting jack embodying two frame members that are spaced apart at their forward end and converge toward their rear end, a caster wheel at the rear end of saidframe members, a transverse axle at the forward end of said frame members, wheels on said axle, a housing mounted between said frame members near the front end, a vertical pressure cylinder in said housing, a lifting plunger in said pressure cylinder, a horizontal pump cylinder communicating with the bottom end vof said pressure cylinder, a liquid reservoir communicating with said pump cylinder, a relief valve between said pressure cylinder and said li uid reservoir, a rod for opening said relie valve, a foot pedalat the rear end of said frame for moving said rod, a piston in said pump cylinder, a pump lever mounted on the rear end of the frame, and operatin means connecting said pump lever and sai piston.

A hydraulic jack embodying a frame,

wheels supporting said frame, a vertical pressure'cylinder mountedon the forward end of said frame, a lifting plunger disposed in said pressure cylinder, a horizontal pump cylinder connected with the bottom end of said pressure cylinder, acheck valve interposed between a said pump cylinder and said pressure cylinder, a liquid reservoir having passageways communicating with said pressure cylinder and said pump cylinder, a relief valve interposed in the passageway between said liquid reservoir and said pump cylinder, means for opening said relief valve, a piston in said pump cylinder, a piston rod connected with said piston, an, oscillating lever 'at the rear end of said frame and a link connecting the said lever with said piston rod.

6. A hydraulic jack embodying a frame, an axle extending crosswise of the front end of said frame, wheels on the ends of said axle, a caster wheel at the rear end of said frame, a housing mounted on the front end of said frame, said housing having a vertically arranged pressure cylinder and a horizontally arranged pump cylinder, and having a liquid reservoir communicating with said pump cylinder, a check valve interposed between said liquid reservoir and said pressure cylinder, foot controlled means operable from the rear end of said frame for opening said check valve, another check valve interposed between said pump cylinder and said pressure cylinder, a piston reciprocable in said pump cylinder, a piston rod connected with said piston, ahand lever pivoted for oscillation at the rear end of said frame and a link connecting said pis= ton rod and said hand lever. I

The foregoing specification signed at Se:

at-tle, VVash., June 8th, 1922.

JOHN B. 'HIRD. JOHN B. HIRD, JR. 

